Ground Control Points (GCPs) are used in the generation of the ortho-rectified imagery, for instance, acting as tie points in images that tie the images to a real-world coordinate frame (e.g., the surface of the Earth). To generate ortho-rectified imagery from a collection of images that are to be combined (e.g., stitched) together, GCPs need to be visible within the collection of images, along with highly accurate location information for each GCP. Generally, to collect this location information, a person can travel a desired location and set-up a tripod system that includes a survey grade GNSS (e.g., GPS) receiver, and visually mark a physical area associated with the GCP. Location information (e.g., coordinates) associated with the GNSS receiver at the physical area are obtained, and stored for use as a GCP.